Combined pressure and vacuum valve for steam-boilers



UNITED STATES PATENT OFFICE.

DANIEL R. PRINDLE, OF EAST BETHANY, NEW YORK.

COMBINED PRESSURE AND VACUUM VALVE FOR STEAM-BOILERS.

Specification of Letters Patent No. 29,004, dated July 3, 1860.

To all 'whom t may concern:

Be it known that I, DANIEL R. PRINDLE, of Bethany, in the county of Genesee and State of New York, have invented a new and Improved Safety or Combined Expansion and Vacuum Valve; and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings, making part of this specification.

Figure l is a side elevation of the valve, together with a portion of a boiler, in which it is represented as located; Fig. 2, a central vertical section of the valve, some of the interior parts, however, being in elevation; Fig. 3, a top view of the valve; and Fig. 4, a bottom view thereof.

Like letters designate corresponding parts in all the gures.

My invention consists in an improved valve, which is used either for safety against excess of internal pressure, or of external pressure, or of both, at different times, in the same boiler, or vessel; and which is entirely complete and independent in itself, requiring nothing but a simple aperture, in the boiler, or vessel, to receive it, and being removable, portable, and transferable, at any moment, and at once. It is particularly applicable where an o-rdinary safety valve is required, and where on the cooling of the water, or liquid, wit-hin, a vacuum is to be guarded against; as, for instance, in case of my improved steam generator, and caldron, patented September 13, 1859, and reissued December 13, 1859; wherein both excess of internal pressure, and a vacuum are to be avoided, and wherein it is frequently desirable to remove the valve entirely.

In the accompanying drawings, A, represents the whole valve; and B, a portion of a boiler, in a simple aperture of which the valve rests, without any other connection whatever. A portion of the valve tube enters the boiler, t-ill a flange c, around the periphery of the tube, rests upon a ground, or plane, surface d, around the aperture in the boiler. The said portion b, of the valve tube, is a little smaller than t-he aperture in the boiler, so as to allow a vent to the steam, as the valve is raised, without throwing the valve out. The weight of the valve is intended to be sufficient to resist the amount of pressure required in the boiler,

particularly if only a constant pressure is required. But for general use, wherein an increase, or variation, of pressure may be required, the valve tube is continued, a proper distance, above the flange c, as at a, so as to receive weights, conveniently in the form of rings, as shown by dotted lines at 29, p, Fig. 1. Thus a complete pressure safety valve is produced, which cannot get out of o-rder, nor fail to yield to the pressure, as soon as raised above the graduation of the valves weight; and which is inserted, and taken out, at any moment, for convenience, either for filling' the boiler through the valve aperture, or to be removed at any moment to gage the water in the boiler through said aperture, or to be removed to another boiler, or vessel.

The vacuum valve it, closes the bottom of the tube b, and opens downward. Its stem g, first extends up through a guide and support bar, f, across the bottom of the tube b; then, above that, it receives a coiled spring m; and above the spring, it has a screw thread, on which a nut z', is turned, to adjust the strength of the spring m, in order to have the valve yield exactly when a partial vacuum commences, or at any excess of inward pressure desired. Also, from the nut z', three or four wings Z, Z, extend radially outward, so as to lit loosely the inside of the valve tube, and thus keep the valve stem g, centered. Instead of making the hub of the wings, as a nut, a separate nut, (as at z', Figs. l, and 2,) may be used. But this is not necessary, nor preferable.

I do not claim simply combining a safety or expansion valve, and a vacuum valve, in one instrument; but

lhat I claim as my invention and desire to secure by Letters Patent, is-

The construction, arrangement, and combination of parts, substantially as herein described, so as to produce a combined expansion and vacuum valve entirely unatt-ached, except by its weight and simple contact, to the boiler, or vessel, in which it is used, and consequently portable, and transferable, for the conveniences and purposes specified.

DANIEL R. PRINDLE.

Witnesses:

J. FRASER, S. J. ALLrs. 

